1. Field of the Invention
The present invention relates to a method and an apparatus for displaying multiple subtitles by sub-picture processing, and particularly to a method and an apparatus for displaying multiple subtitles of a digital versatile disk (DVD) player.
2. Description of Related Art
Optical disks, having the advantages of huge storage capacity, easy preservation, long preservation period, low cost, and damage resistance for saved data, are gradually replacing the general conventional magnetic storage medium and become one of the indispensable optical storage medium. With huge storage capacity, the most commonly seen DVDs nowadays can be recorded with a large volume of subtitles in multiple languages and displayed with a number of subtitles in different languages simultaneously if under proper operation by users when being played.
The conventional method for displaying multiple language subtitles of a DVD is to employ a plurality of sub-picture decoding units to decode the multiple languages subtitles. Consequently, two the sub-picture decoding units are required for displaying two subtitles simultaneously, and three sub-picture decoding units are required for displaying three subtitles simultaneously, and so on. Therefore, the number of the sub-picture decoding units will need to be added if more sub-picture subtitles are to be displayed. As a result, not only will the production costs be increased, lots of extra amendments to the image mixers of the original sub-picture will also be made to meet the function requirements.
FIG. 1 is a flowchart illustrating the process of a conventional DVD player displaying multiple languages subtitles. First, in step 100, the hardware is required to provide an image recording area for a sub-picture. Then in step 102, a first sub-picture is checked to see if it is enabled. If not, the sub-picture processing stops. If yes, in step 104, the sub-picture control and sub-picture image data corresponding to the first sub-picture are requested from the storage media so as to decode the first sub-picture in the first sub-picture unit in step 106. The first sub-pictures is adjusted in step 108 and integrated into the sub-picture image recording area of the sub-picture in step 110 before moving to the processing of the second sub-picture. In step 112, a second sub-picture is checked to see if it is enabled. If it is not, the sub-picture processing stops. If it is yes, in step 114, the sub-picture control and sub-picture image data corresponding to the second sub-picture are requested from the storage media to decode the second sub-picture in the second sub-picture unit in step 116. The second sub-picture is adjusted in step 118 and integrated into the sub-picture image recording area of the sub-picture in step 120. Then, in step 122, the entire image of the sub-pictures is integrated into the image mixer of the main picture. If this method can only enable two sub-pictures, the sub-picture processing stops.
In view of the above, if more sub-pictures are to be enabled, not only will the number of the decoding units of the sub-pictures increase, the corresponding additional steps will also rise. Hence, a solution to the above is provided in the present invention.